The third skill manual he chose is the Concealment technique, which he named the "Invisibility Technique." This technique allowed the user to blend into their surroundings, making them nearly invisible to the naked eye. The technique also included methods to mask the user's aura, making it even harder for opponents to sense their presence. This technique is divided into five levels, each with its own unique abilities and benefits.

Level 1: At the first level, the cultivator is able to conceal their presence and hide their aura, making them difficult to detect by those with weaker cultivations. This level can also be used to hide in shadows and blend into the background.

Level 2: At the second level, the cultivator is able to conceal their physical form, making them invisible to the naked eye. This level is useful for sneaking past guards or avoiding detection in enemy territory.

Level 3: At the third level, the cultivator is able to conceal their voice and footsteps, making it difficult for others to track them. This level is useful for infiltration and reconnaissance missions.

Level 4: At the fourth level, the cultivator is able to conceal their scent, making them difficult to track by beasts or cultivators with heightened senses. This level is useful for hunting or avoiding detection in the wild.

Level 5: At the fifth level, the cultivator is able to conceal their entire being, including their presence, physical form, voice, footsteps, and scent. This level is useful for assassination or infiltrating heavily guarded areas. With this level, cultivators can even conceal their cultivation base.

Reading the description of the fifth level invisible technique, Han Cai had an evil smile on his face.

The fourth manual Han Cai chose was something to save his life. It was called the element escape technique. It was a highly advanced and versatile skill manual that allowed cultivators to escape through different elements such as earth, water, fire, and air. The skill manual is divided into different levels, each unlocking new abilities and capabilities.

At level one, practitioners of the Element Escape Technique can use it to escape through the earth. This means they can move underground and even hide in the earth. This ability is particularly useful for evading pursuit or hiding during battle.

At level two, practitioners can escape through the water. They can swim through rivers, lakes, and even oceans and can even control the water to conceal their movements. This level also enables the user to control water to a certain extent.

At level three, practitioners can escape through the fire, and they can move through flames, and even manipulate fire to conceal their movements or create a diversion.

At level four, practitioners can escape through the air. They can fly and control the wind, making it difficult for enemies to detect or track them.

Overall, the Element Escape Technique was a powerful and versatile skill manual that could greatly enhance his ability to evade pursuit, escape danger, and conceal his movements. It's a perfect skill for Han Cai as it would increase his chances of survival and success.